The proposed research consists of two projects: (1) It has been observed in Lilium 'Croft' that laggard cells in premeiotic mitosis do not complete this division; the chromosomes despiralize to interphase and the cells enter into meiosis (Walters, 1978). It was proposed that the mitotic divisions could not be completed because the reproductive organ (anther) had reached a state of physiological preparedness for meiosis, or "meiosis readiness". The mechanism of meiosis induction has not been determined in any organism. However Byskov and Saxen (1976) suggested that meiosis-inducing substances, produced outside the reproductive organ, may initiate meiosis in mammalian germ cells. Present evidence from Lilium is in agreement with this suggestion. The observation of "meiosis readiness" in Lilium 'Croft' is the first of its kind. It is therefore necessary to determine whether this state can be identified in other materials. (2) Preleptotene chromosome contraction has been observed in Lilium (Walters, 1970, 1972, 1977) and also in human meiosis (Luciani, et al., 1977). The significance of this stage has not been established. Walters (1977) proposed that the degree of pzeleptotene chromosome contraction depends on the duration of the contraction phase. Preliminary observations by the applicant suggest that localized fluctuations in rate of meiosis may occur within the reproductive organ of Lilium 'Croft'. Fluctuations of this nature have not been reported previously. Their occurrence may explain some differences in constitutions of sex cells within reproductive organs not hitherto accounted for (Henderson, 1970). Both projects require studies of premeiosis and meiosis in a number of materials; Lilium is especially favorable material for studies of sequential development of pemeiotic and meiotic cells in the reproductive organ.